Effective self-purification of polynary metal electroplating wastewaters through formation of layered double hydroxides

Zhou, JZ, Wu, YY, Liu, C, Orpe, A, Liu, QA, Xu, ZP, Qian, GR and Qiao, SZ (2010) Effective self-purification of polynary metal electroplating wastewaters through formation of layered double hydroxides. Environmental Science and Technology, 44 23: 8884-8890. doi:10.1021/es102884v


Author Zhou, JZ
Wu, YY
Liu, C
Orpe, A
Liu, QA
Xu, ZP
Qian, GR
Qiao, SZ
Title Effective self-purification of polynary metal electroplating wastewaters through formation of layered double hydroxides
Journal name Environmental Science and Technology   Check publisher's open access policy
ISSN 0013-936X
1520-5851
Publication date 2010-12-01
Year available 2010
Sub-type Article (original research)
DOI 10.1021/es102884v
Open Access Status DOI
Volume 44
Issue 23
Start page 8884
End page 8890
Total pages 7
Place of publication Washington D C, United States
Publisher American Chemical Society
Language eng
Abstract Heavy metal ions (Ni(2+), Zn(2+), and Cr(3+)) can be effectively removed from real polynary metal ions-bearing electroplating wastewaters by a carbonation process, with similar to 99% of metal ions removed in most cases. The synchronous formation of layered double hydroxide (LDH) precipitates containing these metal ions was responsible for the self-purification of wastewaters. The constituents of formed polynary metals-LDHs mainly depended on the Ni(2+):Zn(2+):Cr(3+) molar ratio in wastewaters. LDH was formed at pH of 6.0-8.0 when the Ni(2+)/Zn(2+) molar ratio >= 1 where molar fraction of trivalent metal in the wastewaters was 0.2-0.4, otherwise ZnO, hydrozincite, or amorphous precipitate was observed. In the case of LDH formation, the residual concentration of Ni(2+), Zn(2+), and Cr(3+) in the treated wastewaters was very low, about 2-3, similar to 2, and similar to 1 mg/L, respectively, at 20-80 degrees C and pH of 6.0-8.0, indicating the effective incorporation of heavy metal ions into the LDH matrix. Furthermore, the obtained LDH materials were used to adsorb azoic dye GR, with the maximum adsorption amount of 129-134 mg/g. We also found that the obtained LDHs catalyzed more than 65% toluene to decompose at 350 degrees C under ambient pressure. Thus the current research has not only shown effective recovery of heavy metal ions from the electroplating wastewaters in an environmentally friendly process but also demonstrated the potential utilization of recovered materials.
Formatted abstract
Heavy metal ions (Ni2+, Zn2+, and Cr3+) can be effectively removed from real polynary metal ions-bearing electroplating wastewaters by a carbonation process, with ∼99% of metal ions removed in most cases. The synchronous formation of layered double hydroxide (LDH) precipitates containing these metal ions was responsible for the self-purification of wastewaters. The constituents of formed polynary metals-LDHs mainly depended on the Ni2+:Zn2+:Cr 3+ molar ratio in wastewaters. LDH was formed at pH of 6.0-8.0 when the Ni2+/Zn2+ molar ratio ≥ 1 where molar fraction of trivalent metal in the wastewaters was 0.2-0.4, otherwise ZnO, hydrozincite, or amorphous precipitate was observed. In the case of LDH formation, the residual concentration of Ni2+, Zn2+, and Cr3+ in the treated wastewaters was very low, about 2-3, ∼2, and ∼1 mg/L, respectively, at 20-80 °C and pH of 6.0-8.0, indicating the effective incorporation of heavy metal ions into the LDH matrix. Furthermore, the obtained LDH materials were used to adsorb azoic dye GR, with the maximum adsorption amount of 129-134 mg/g. We also found that the obtained LDHs catalyzed more than 65% toluene to decompose at 350 °C under ambient pressure. Thus the current research has not only shown effective recovery of heavy metal ions from the electroplating wastewaters in an environmentally friendly process but also demonstrated the potential utilization of recovered materials. © 2010 American Chemical Society.
Keyword Zn-Cr-Cl
Waste-water
Heavy metals
Accelerated carbonation
Q-Index Code C1
Q-Index Status Confirmed Code
Grant ID 20907029
S30109
DP1095861
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2011 Collection
Australian Institute for Bioengineering and Nanotechnology Publications
 
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Created: Sun, 19 Dec 2010, 10:13:59 EST